diff --git a/impfilesbk b/impfilesbk
index d02b0d9..f111248 100644
--- a/impfilesbk
+++ b/impfilesbk
@@ -2,6 +2,9 @@
 
 # This script backs up some important stuff
 
+# Run only one instance of this script at one time
+[ "${BKLOCKER}" != "running" ] && exec env BKLOCKER="running" flock -en "/tmp/impfilesbk" "$0" "$@" || :
+
 # Setup location for home and backup directory
 HMDIR="/home/sintan"
 BKDIR="/mnt/storage/sintan"